During some injuries, soft tissue, such as tendons or ligaments, can tear away from hard tissue, such as bone. Accordingly, it becomes necessary to reattach the soft tissue to the bone in order to facilitate the healing process. Various types of devices are used to reattach tissue, such as screws, staples and suture anchors. The instant invention relates to this latter type of attachment device.
Suture anchors may be inserted into a preformed hole made in the hard tissue, while other anchors are self-tapping. The anchors typically include an eyelet or other structure through which lengths of repair suture or working suture are threaded, which working suture is inserted simultaneously with the anchor into the hard tissue. In this regard, in some anchors, the eyelet is disposed exteriorly on the anchor, for example adjacent to or even forming part of a drive head located on the proximal end of the anchor, and in other anchors is formed interiorly within a bore defined inside the anchor. The eyelet may be formed from suture material, as disclosed in U.S. Pat. No. 6,641,597, and in other instances is formed as a rigid and integral component of the anchor body, as disclosed in U.S. Pat. No. 5,584,836. A further suture-engaging structure is disclosed in U.S. Patent Publication No. 2005/0222618, wherein the anchor incorporates a rigid pin disposed transversely across an interior bore defined in the anchor. In this variation, the working sutures are inserted into the proximal end of the anchor bore and looped over the pin to secure the suture to the anchor.
It has also been discovered that increasing the biological integration of the suture anchor with the bone in which the anchor is implanted can reduce rejection potential and speed healing. One embodiment of a suture anchor according to the invention is hollow and includes a continuous through-bore, so that the tip or distal end of the anchor, which is embedded in the bone tissue, is open, allowing the permeation/migration of blood, bone marrow, and their components (including platelets and mesenchymal stem cells) into the repair site. The anchor is further formed of a bio-absorbable material, which also enhances healing and integration of the suture and anchor into the bone tissue.
An inserter device or driver may be utilized in conjunction with the anchor to install or drive same into hard tissue and may carry working sutures thereon. For the purpose of providing pull-out resistance once the anchor is installed, some anchors are exteriorly threaded, while others are ribbed or barbed to provide appropriate pull-out resistance.
The suture anchor according to the present invention includes an anchor body having a distal end configured for insertion into hard tissue and a proximal end spaced from the distal end. The anchor body carries thereon a suture engagement structure which cooperates with working suture to attach same to the suture anchor. The suture-engaging structure may, according to one embodiment, be defined by suture material, and may be formed as a continuous loop of suture material having a portion thereof located interiorly of the anchor, such that the working suture is looped over this interior portion of the suture loop to engage the working suture with the anchor.
The suture anchor according to the invention in one embodiment is configured for cooperation with an inserter or driver device. The inserter device includes a handle for manipulating the device and an inserter shaft which supports the suture anchor at the distal end thereof. The inserter device carries working sutures, which working sutures are engaged with the anchor via the suture engagement structure as discussed above, and then extend proximally either interiorly or exteriorly of the inserter device.
One possible use of the arrangement is in arthroscopic shoulder surgery, wherein the dislocation of soft tissue relative to the bone is a fairly common injury. However, this arrangement may also be utilized for the repair of small joints, such as the elbow, wrist, ankle, hand or foot. The arrangement may additionally be used to reattach small ligaments in the knee.
Other objects and purposes of the invention will be apparent to persons familiar with arrangements of this general type upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center and designated parts of thereof. The word “distally” will refer to the direction towards the end of the arrangement located closest to the patient, and the word “proximally” will refer to the direction towards the end of the arrangement located remote from the patient. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.